Alpha Protocol

This is a rather problematic trophy, because to get it you need to kill almost everyone in the game. The hint contains a lot of plot spoilers, so I don’t recommend using it if you haven’t played through the game at least once before. Read the hint from beginning to end, because... I will try to present in it a plan for completing the game, which you should follow in order to get the trophy:

1) From the very beginning of the game until you meet in Rome in a cafe with Marburg, try to answer mostly in dialogues (Suave), because If you don't do this, there's no way you can kill him in Rome. You can use this answer option from a conversation with Yancy Westridge and Sean Darcy, because reputation with them is absolutely not important to you, and you will kill Darcy in any case, even if you have a big plus in reputation with him.
2) You need to try to lower your relationship with Mina from the very beginning of the game (if you can’t do this through dialogues, you can easily do this by killing civilians, such as CIA agents in Rome, as well as police officers on missions in the subway and hotel in Taipei) .
3) It is imperative that you maintain good relations with Steven Heck in Taipei, because... he is the only assistant who can kill Scarlet in the ending. (If you go on some missions in Taipei before meeting him, you will automatically receive -2 upon meeting).
4) You also need to make your relationship with Scarlet as bad as possible so that she intends to kill you at the end of the game, otherwise you will simply not be able to kill everyone.

In general, this was the game plan, and below I will describe what you will need to do to get the trophy:

1) In Saudi Arabia you need to kill Nasri and Shahid.
2) In Moscow you need to kill Little Sister, as well as Zee or Albatross, depending on who you choose as an assistant for the mission Intercept Surkov at US embassy, ​​and the assistant will already transfer to the mission to the Braiko mansion (personally, I killed Albatross, and with my own hands , but, as they write on many sites, you can kill either Zee or him. I also don’t know if you will be counted as a murder if you don’t go to save them and leave them to die, so it’s better not to risk it).
Next, kill Braiko himself (first you need to go through 3 rounds of dialogue with him, after which he will hand over Surkov to you and another mission will open, if you don’t do this, you won’t kill Surkov either and you won’t get the trophy). Next, go to the opened mission and kill Surkov.
3) In Rome you will have to kill the ice cream man and CIA agents on a mission (nowhere is it said why, but just in case it’s worth doing), then you need to kill Jibtil Al'Bara, and then kill Marburg and Maddison in the museum (so you can kill her you need to choose East Wing, I also read on some sites that her death is optional, but to be sure, kill her).
4) In Taipei everything is quite simple, on the last mission kill Omen Deng, and also after the Intersept Assasination Plans mission you must save information about the Riots, which will allow the president to die.
5) In Endgame, they advise you not to meet with your allies before a mission in the Alpha Protocol (there is essentially only one ally left - Scarlet, and you are on bad terms with her, so there is simply no point in meeting). Further in order. We definitely choose Steven Heck as an assistant, only he allows us to achieve the desired ending. When talking with Leland, if you have a good reputation with him, refuse the alliance; if you have a bad reputation, he won’t even offer it. Next, contact Alan Parker on your computer and always answer him (Aggressive), which will provoke it. Skip the room with Scarlet (I don’t know if it’s necessary, they advised me to skip it - I didn’t go), then kill Mina (or rather, the option should be Leave her, but for some reason she lies dead after the conversation). Then you kill Alan Parker, leave the Alpha Protocol and already on the street you kill Darcy, the helicopter, and in the end you defeat Leland. First, let him go (Spare), after which Scarlet should come and shoot you, then (if you did everything as described and installed Steven Heck and are on good terms with him) your assistant comes and kills her, after which you again have the opportunity kill Leland - do it and the trophy is yours.

PS There is also an alternative and simpler option for killing Marburg, but it’s not a fact that it will work, because... Personally, I did not try it when receiving this trophy. In Rome, you need to collect 100% of the dossier on Maddison, then start an affair with her and in a conversation, after you sleep, reveal a secret fact. Then go to the museum in East Wing, after which Marburg will kill her. Having a 100% dossier and a secret fact on the last mission when contacting Alan Parker will add an answer option (Maddison). If you choose him, Marburg will kill Parker and you will fight him instead of Parker. In theory it should work, because, as the trophy asks, everyone is dead in the end, but this option has not been tested, so try it at your own risk.